Development and Research of the Characteristics of the Parametric Laser on the AGS Crystal

The paper presents the results of computational and experimental studies of the characteristics of an extracavity parametric laser on an active element made of silver thiagallate (AGS) crystal, which converts the main radiation of a YAG: <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{N d}^{\mathbf{3 +}}$</tex> laser into the near and mid-IR range. A design of an unstable telescopic resonator of a YAG: <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{Nd}^{\mathbf{3 +}}$</tex> pump laser with an output radiation wavelength of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$1.064 \mu ~\mathrm{m}$</tex>, a pulse repetition rate of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{3 0 ~ H z}$</tex>, a divergence of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{1. 5 ~ m r a d}$</tex>, and also a maximum output energy of 180 mJ is presented. The following output radiation characteristics were obtained for the developed parametric laser: divergence <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\boldsymbol{\theta}=\mathbf{1.3}$</tex> mrad, output radiation energy up to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{11}$</tex> mJ, and smooth wavelength tuning from 1.41 to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$9.01 \mu ~\mathrm{m}$</tex>. Tuning curves for angular tuning are presented. The use of the FabryPerot standard as a dispersing element allowed us to narrow the spectral width of the output radiation to a level of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$1 ~\text{cm}^{-1}$</tex>. In general, the obtained characteristics allow us to speak about the efficiency of using the developed parametric laser as a highly monochromatic source of optical radiation for lidar monitoring systems of the amosphere state, in particular for remote and operational study of the physicochemical structures of complex organic molecules.